Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Analysis of EUV spectra from N-shell tungsten ions observed with an electron beam ion trap



Tapasi Das, Yuri Podpaly, Joseph Reader, John D. Gillaspy, Yuri Ralchenko


Extreme ultraviolet spectra of highly charged tungsten ions were produced with an electron beam ion trap at the National Institute of Standards and Technology and recorded with a flat-field grazing-incidence spectrometer. The spectra were measured in the wavelength range 2.7 nm to 17.3 nm while the beam energy varied between 1.65 keV and 2.00 keV. At these energies, the ionization stages from Zr-like W34+ to Se-like W40+ ions were observed. Large-scale collisional-radiative modelling was used to identify the strong lines, including 15 new ones, which represent electric dipole n = 4-4 transitions in these ions. While a good quantitative agreement between theoretical and experimental data was found for almost all ions, some of the tentatively identified wavelengths in W35+ significantly disagree from all available calculations.
European Journal of Physics


EBIT, EUV, tungsten, highly-charged ions, spectra, collisional-radiative modeling
Created July 3, 2018, Updated October 9, 2019